More than 7,000 slaves owned by Arissal Ag Amdague, a Tuareg tribal chief, were due to be released at a desert ceremony last Saturday in the village of In Atès, 175 miles northwest of Niger's capital, Niamey.

A new law that came into effect last year was supposed to finally punish masters, who had long held slaves with little hassle from the government. Anti-Slavery International, the world's oldest human rights group, billed the event as unlike anything seen since the abolition of the transatlantic slave trade.

Despite the government's positive move to announce the new law and its willingness to apply it, it sent out mixed messages later by saying slavery no longer exists in Niger. This contradicts eyewitness reports from international and local rights groups, and a signed statement from Chief Arissal promising to free his "enslaved people," a copy of which Anti-Slavery International has in its possession.

Slavery is widespread across the Sahel Desert region, in countries that include Niger, Mali, Mauritania, Chad, and Sudan, according to rights groups. Anti-Slavery International (www.antislavery.org) and Timidria, a local rights group, calculate there are at least 43,000 slaves still in Niger. Slavery dates back centuries but was outlawed at independence from France in 1960, however the Constitution carried no penalty, and the postcolonial administrations turned a blind eye.

But a May 2003 change in Niger's penal code, which came into force a year later, criminalized slavery and introduced a 30-year maximum jail term. It was the fear of imprisonment that forced Chief Arissal initially to agree to free his slaves.

However, a government delegation toured the chief's fiefdom in the weeks before Saturday, harassing the slaveholders into backtracking on their pledges to free their slaves, Anti-Slavery International claims.

David Ould, deputy director of the London-based group, says: "The enactment of legislation that criminalizes and penalizes slavery does not automatically mean it has been eliminated. It is vital the Niger Government acknowledges that slavery is a serious problem throughout the country and ensures that those in slavery are made fully aware of the new law and released."

Azara, 25, was born into slavery, and has two young children conceived when she was raped by her master. She escaped two years ago by running through the desert for two days and was taken into the care of Timidria. "I was worked so hard, I had to pound millet and fetch water, day and night," she says. "I was considered [my master's] animal. It was out of the question to say no. If I ever I refused I was beaten."

It's not clear what the event marking no slaves being released was supposed to signal. But some see it as progress.

Romana Cacchioli, Africa program officer for Anti-Slavery International, wishes the public was invited to Saturday's event so they could hear the declaration that Niger is slave free. She calls the announcement "a de facto release of all Nigerien slaves. Now they are equal citizens," she says. "Now we will redouble efforts on the ground for civic education, for human rights education, about what it means to be a citizen, what it means to be free."